It is common practice to pass electrical conductors and cable through conduit (typically metal conduit) from one point to another as a means of providing support and protection for the conductors and the cables. The term "conduit" refers to pipe having dimensional and other characteristics suitable for use by the electrical industry as is well known by those ordinarily skilled in the art. Although hereinafter referred to as conduit, it is to be understood that the term "conduit" as used herein means conduit made from metallic or heat stable polymeric materials and includes pipe made from metal or heat stable polymeric materials that, although not conduit, is able to serve the purpose of conduit where such is desired.
Conduit may often inadvertently or unavoidably provide a passageway from a region in which explosive, corrosive, toxic or otherwise undesirable vapors are present to a region free of such vapors. In an effort to prevent the passage of such vapors through the conduit, it has been common practice in the past to pack the openings between the conduit and the conductors and cable with some type of heavy pliable material to provide a barrier to the flow of such vapors through the conduit. In recognizing the problem, minimum performance criteria has been established under relevant sections of the National Electrical Code for controlling the manner in which conduit located in hazardous locations is sealed.
The manner in which conduit has been sealed in the past however has typically involved expensive fittings of complex design that are commonly adapted to be used in conjuction with sealant materials which may require mixing of several components to impart sufficient viscosity to withstand the pressure of the vapors and require costly inventory of components.
One method commonly used at the present time for sealing electrical conductors at a junction between conduits is to use metal connectors sold by Crouse-Hinds Company under series numbers EYS, EZS, EYD, EZD and ECD. The connectors feature a port-filling entrance into which a sealant, recommended and sold by Crouse-Hinds Company under the trademark "Chico", can be poured into their connector to provide a barrier against the flow of vapor through the conduits in conjunction with the use of a fiber sold by Crouse-Hinds under the trademark "Chico X Fiber" for providing a dam within the connector to prevent the flow of the sealing compound into the ends of the conduits.
The complexities, costs and requirement to inventory multiple components of prior-art systems and the need to provide a simpler and lower cost method of connecting metal conduit together and provide a barrier against the flow of vapor through the conduits represents a problem which, although long known to industry, has not, up until the time of the present invention, had a completely satisfactory solution.